644446463 has 2 divisors, whose sum is σ = 644446464. Its totient is φ = 644446462.

The previous prime is 644446433. The next prime is 644446511. The reversal of 644446463 is 364644446.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 644446463 - 2⁶ = 644446399 is a prime.

It is a super-2 number, since 2×644446463² = 830622487346420738, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 644446463.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644446403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322223231 + 322223232.

It is an arithmetic number, because the mean of its divisors is an integer number (322223232).

Almost surely, 2^644446463 is an apocalyptic number.

644446463 is a deficient number, since it is larger than the sum of its proper divisors (1).

644446463 is an equidigital number, since it uses as much as digits as its factorization.

644446463 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 663552, while the sum is 41.

The square root of 644446463 is about 25385.9501102480. The cubic root of 644446463 is about 863.7650248182.

It can be divided in two parts, 64444 and 6463, that added together give a palindrome (70907).

The spelling of 644446463 in words is "six hundred forty-four million, four hundred forty-six thousand, four hundred sixty-three".